Milton Roy MILROYAL D User manual

MILROYAL®D DISC DIAPHRAGM
Low Flow Liquid End
Instruction Manual
Manual No : 54248
Rev. : 01
Rev. Date : 05/2019

iInstruction Manual
PRECAUTIONS
The following precautions should be taken when working with metering pumps.
Please read this section carefully prior to installation.
Protective Clothing
ALWAYS wear protective clothing, face shield, safety glasses and gloves when working on or
near your metering pump. Additional precautions should be taken depending on the solution
being pumped. Refer to Safety Data Sheets for the solution being pumped.
Hearing Protection
It is recommended that hearing protection be used if the pump is in an environment where the
time - weighted average sound level (TWA) of 85 decibels is exceeded. (as measured on the
A scale - slow response)
Electrical Safety
• Remove power and ensure that it remains off while maintaining pump.
•DO NOT FORGET TO CONNECT THE PUMP TO EARTH/ GROUND.
• Electric protection of the motor (Thermal protection or by means of fuses) is to correspond
to the rated current indicated on the motor data plate.
Liquid Compatibility
Verify if the materials of construction of the wetted components of your pump are
recommended for the solution (chemical) to be pumped.
Pumps Water “Primed”
All pumps are tested with water at the factory. If your process solution is not compatible with
water, ush the Pump Head Assembly with an appropriate solution before introducing the
process solution.
Plumbing and Electrical Connections
Always adhere to your local plumbing and electrical codes.
Line Depressurization
To reduce the risk of chemical contact during disassembly or maintenance, the suction and
discharge lines should be depressurized before servicing.
Over Pressure Protection
To ensure safe operation of the system it is recommended that some type of safety/pressure-
relief valve be installed to protect the piping and other system components from damage due
to over-pressure.
Lifting
This manual should be used as a guide only - Follow your company’s recommended lifting
procedures. It is not intended to replace or take precedence over recommendations, policies
and procedures judged as safe due to the local environment than what is contained herein.
Use lifting equipment that is rated for the weight of the equipment to be lifted.

iiInstruction Manual
SECTION 1 - DESCRIPTION ................................................................ 1
1.1 GENERAL ...................................................................... 1
1.2 PRINCIPLE OF OPERATION ....................................................... 1
1.3 SAFETY PRECAUTIONS........................................................... 1
1.4 MODEL CODING................................................................. 1
SECTION 2 - STORAGE .................................................................... 3
2.1 STORAGE ...................................................................... 3
2.1.1 Short Term Storage (Less than 6 Months) ............................................ 3
2.1.2 Long Term Storage(Longer than 6 Months) ........................................... 3
2.1.3 Pump Drive and Gearboxes ....................................................... 3
2.1.4 Pneumatic, Electrical and Electronic Equipment........................................ 3
SECTION 3 - INSTALLATION ................................................................ 5
3.1 UNPACKING .................................................................... 5
3.2 MOUNTING ..................................................................... 5
3.3 LIQUID END CONVERSION........................................................ 5
3.4 MILROYAL®D CONVERSION STEPS ................................................ 5
3.4.1 Disassembly ................................................................... 5
3.4.2 Reassembly ................................................................... 5
3.5 PIPING ....................................................................... 5
3.6 GENERAL INFORMATION ......................................................... 6
3.7 SUCTION PIPING ................................................................ 6
3.8 DISCHARGE PIPING ............................................................. 6
3.9 PIPING CONCENTRATED SULFURIC ACID ........................................... 6
3.10 SUCTION LIFT CONDITIONS...................................................... 7
SECTION 4 - OPERATION .................................................................. 8
4.1 INITIAL START-UP................................................................ 8
4.2 MAINTENANCE ................................................................. 9
4.3 CHECK VALVES ................................................................. 9
4.4 DISASSEMBLY ................................................................. 10
4.5 DIAPHRAGM................................................................... 10
4.6 REASSEMBLY.................................................................. 10
SECTION 5 - TROUBLESHOOTING GUIDE .................................................... 12
TABLE OF CONTENTS

iii Instruction Manual
LIST OF ILLUSTRATIONS
FIGURE 1. Model Code ..................................................................... 2
FIGURE 2. Data Plate....................................................................... 2
FIGURE 3. Standard Dimensions.............................................................. 4
FIGURE 4. Typical Sludge Trap ............................................................... 7
FIGURE 5. Typical Installation ................................................................ 7
FIGURE 6. Milroyal®D Disc Diaphragm Liquid End Top View ....................................... 13
FIGURE 7. Milroyal®D Disc Diaphragm Liquid End Section View .................................... 14
FIGURE 8. Double Ball Suction & Discharge Valve ............................................... 17
FIGURE 9. Single Ball And Double Ball Check Valve Assemblies .................................... 18
FIGURE 10. Double Ball Suction & Discharge Valve .............................................. 20
FIGURE 11. Rell Valve Assembly............................................................. 22
FIGURE 12. Relief Valve Assembly............................................................ 23

1Instruction Manual
The instruction manual is designed to serve
as a supplement to instruction manual 53941,
which provides both general information and
specic instructions for installing, operating, and
maintaining Milroyal®pumps. This manual covers
only the optional Low Flow Disc Diaphragm Liquid
Ends which may be tted to these pumps in place
of the standard Packed Plunger or HPD Liquid
Ends. Do not rely on this manual alone in installing,
maintaining, and operating Milroyal®pumps.
1.1 GENERAL
The Low Flow Disc Diaphragm Liquid End is
particularly suitable for pumping costly, aggressive,
or hazardous liquids without leaking. The diaphragm
is hydraulically balanced between the process
liquid on one side and the hydraulic oil on the
other side. The hydraulic oil takes the place of a
mechanical connection between pump plunger
and diaphragm.
1.2 PRINCIPLE OF OPERATION
In a Disc Diaphragm Liquid End, the reciprocating
pump plunger alternately forces hydraulic oil
against the diaphragm and then draws the oil
back into the plunger bore. This action causes the
diaphragm to ex between the limiting contour
plates.
Each suction stroke of the plunger pulls the
diaphragm towards the oil side contour plate so
that process liquid ows into the displacement
chamber through the suction ball-check valve.
Each discharge stroke of the plunger pushes the
diaphragm towards the process side contour plate
to expel the process liquid from the displacement
chamber through the discharge ball-check valve.
On each suction stroke, the discharge ball-checks
are seated, and on each discharge stroke, the
suction ball-checks are seated (pressure in
pump head is greater than suction line pressure).
This mode of operation prevents back ow and
ensures liquid movement from the suction port,
through the diaphragm head, and out the discharge
port. Precise hydraulic oil volume is maintained
by an automatic air-bleed valve and a rell valve.
1.3 SAFETY PRECAUTIONS
When installing, operating, and maintaining the Disc
Diaphragm Liquid End, keep safety considerations
foremost. Use proper tools, protective clothing, and
eye protection when working on the equipment
and install the equipment with a view toward
ensuring safe operation. Follow the instructions in
this manual and take additional safety measures
appropriate to liquid being pumped. Be extremely
careful in the presence of hazardous substances.
(e.g. corrosives, toxins, solvents, acids, caustics,
ammables etc.)
1.4 MODEL CODING
See Figure 1 to determine the specic features and
ratings of a specic Milroyal®D disc diaphragm
pump. The model code can be found on the product
data plate (see Figure 2) which is mounted on each
pump (see Figure 3).
SECTION 1 - DESCRIPTION

2Instruction Manual
Figure 2. Data Plate
MILTON ROY
2.25
2.25
2.00
2.00
0.13
0.13
WWW.MILTONROY.COM
FLOW CONTROL DIVISION
[phone]
PRODUCT
CODE
SERIAL
NUMBER
RATED
CAPACITY
RATED
PRESSURE
0.13 HOLE
4 PLCS
CC = Nema 143TC
JD = Mount for
Servo Motor
10 = 116 SPM
C5= Rupture Detection with gauge
SN= Rupture Detection with gauge & Nema 4 Switch
SE= Rupture Detection with gauge & Nema 7 Switch
Note: All leak detection options are limited to
400 psig max. discharge pressure.
Figure 1. Model Code

3Instruction Manual
2.1 STORAGE
2.1.1 Short Term Storage (Less than 6 Months)
It is preferable to store the material under a shelter
in its original package to protect it from adverse
weather conditions. In condensing atmospheres,
follow the long term storage procedure.
2.1.2 Long Term Storage
(Longer than 6 Months)
The primary consideration in storage of pump
equipment is to prevent corrosion of external and
internal components. This corrosion is caused
by natural circulation of air as temperature of the
surroundings change from day to night, day to day,
and from season to season. It is not practical to
prevent this circulation which carries water vapor
and other corrosive gases, so it is necessary to
protect internal and external surfaces from their
effects to the greatest extent possible.
When the instructions given in this section are
completed, the equipment is to be stored in a
shelter, protected from direct exposure to weather.
The prepared equipment should be covered with
a plastic sheet or a tarpaulin, but in a manner
which will allow air circulation. Equipment should
be stored 12” or more above the ground.
If equipment is to be shipped directly from
Milton Roy into long term storage, contact Milton
Roy to arrange for factory preparation.
2.1.3 Pump Drive and Gearboxes
A. Flood the gearbox compartment with a high
grade lubricating oil / rust preventative such as
Mobile Oil Corporation product Mobilarma 524.
Fill the compartment completely to minimize
air space and water vapor condensation.
After storage, drain this material and rell the
equipment with the recommended lubricant for
equipment commissioning.
B. Remove drive motors and mounting adapters,
and brush all unpainted metal surfaces with
multipurpose grease (NLGI grade 2 or 3). Store
these unattached.
2.1.4 Pneumatic, Electrical and Electronic
Equipment
A. Motors should be prepared in the manner
prescribed by their manufacturer. If information
is not available, dismount and store motors as
indicated in step “B” below.
B. For all pneumatic and electrical equipment,
place packets of Vapor Phase Corrosion
Inhibitor (VPCI) inside of the enclosure, then
place the entire enclosure, with additional
packets, inside a plastic bag. Seal the bag tightly
closed. Contact Milton Roy Service Department
for recommended VPCI materials.
SECTION 2 - STORAGE

4Instruction Manual
Figure 3. Standard Dimensions
(3) 0.44 (11) DIA
MOUNTING HOLES
24.05 (611)
MAX.
FOR LARGEST
AVAILABLE MOTOR
20.07 (510)
MAX.
0.47 (12)
SUCTION CONNECTION
1/4 -18 NPT MALE
DISCHARGE CONNECTION
1/4 -18 NPT MALE
8.32 (211)
16.32 (414)
MOTOR 1.87 (47)
8.30 (211)
5.00 (127)2.45 (62)
6.75 (171)
10.10 (257)
5.00 (127)
7.50 (191)
3.44 (87)
5.87
(149)
1.31 (33)
GENERAL MOTOR SHOW
* NAME FRAME MTR
* IEC FRAME MTR
(3) Ø 7/16 MTG HOLES
PUMP
1.19 (30)
C
L
C
L

5Instruction Manual
SECTION 3 - INSTALLATION
3.1 UNPACKING
Units are shipped Ex Works , Ivyland , Pa. and the
title passes to the customer when the carrier signs
for receipt of the unit. In the event that damages
occur during shipment, it is the responsibility of the
customer to notify the carrier immediately and to
le a damage claim. Carefully examine the shipping
crate upon receipt from the carrier to be sure there
is no obvious damage to the contents. Open the
crate carefully so accessory items fastened to the
inside of the crate will not be damaged or lost.
Examine all material inside the crate and check
against the packing list to be sure that all items are
accounted for and intact.
3.2 MOUNTING (Refer to Figure 3)
Milroyal® D pumps should be rmly mounted in
a level position on a solid foundation, preferable
with the base above oor level to protect it from
wash downs and provide easier access for service.
This model pump is provided with three tie-down
points to accommodate anchor bolts. Table-top
operation is possible without need for tie-down with
1/8” or 3/16” plunger diameter liquid end. Up to six
units can be easily multiplexed to a single standard
motor without special support.
3.3 LIQUID END CONVERSION
(IF YOU PURCHASED A NEW PUMP THAT HAS
A DISC DIAPHRAGM ALREADY INSTALLED,
PROCEED TO PIPING.)
To convert a pump from standard Packed Plunger
Liquid End to Disc Diaphragm Liquid End, study
the drawings at the back of this manual and then
mount the liquid end to the pump as follows.
3.4 MILROYAL®D CONVERSION STEPS
(SEE FIGURE 7)
3.4.1 Disassembly
1. Remove Packed Plunger Liquid End assembly
from pump (see pump drive disassembly
instructions in instruction manual 53941).
2. Remove plunger adapter, gland cap, gland studs
or bolts, and funnel.
3.4.2 Reassembly
1. Slide plunger adapter over plunger.
2. Insert plunger assembly in bore of displacement
chamber.
3. Carefully fit liquid end assembly to pump
housing bore while guiding plunger adapter into
threaded hole in crosshead.
4. Thread three mounting bolts into displacement
chamber from inside pump catchall and tighten
securely. Use pipe dope on the upper most
screw to insure a proper oil seal.
5. Bottom the plunger rmly in plunger adapter
against crosshead and then tighten adapter
securely.
6. Proceed to start-up instructions in Section 4.
3.5 PIPING
General piping instructions are given below.
Additional information is provided in pump drive
instruction manual 53941. No reciprocation plunger
pump can be expected to perform satisfactorily
unless all recommendations are followed.

6Instruction Manual
SECTION 3 - INSTALLATION
3.6 GENERAL INFORMATION
Use piping materials that are resistant to corrosion
by the liquid being pumped. Use care in selection
of materials to avoid galvanic corrosion at points
of connection to the pump liquid end.
Use piping sufciently heavy to withstand maximum
pressures.
Blow out all lines before making nal connections
too pump.
Provide for pipe expansions when hot uids are
to be pumped. Support piping so that pipe weight
is not placed on the pump. Never spring piping to
make connections.
Piping should be sloped in a manner to prevent
tapping of vapor pockets. Vapor present in liquid
end will cause inaccurate pump delivery.
3.7 SUCTION PIPING
If possible use metal or plastic tubing for the suction
line because tubing has a smooth inner surface and
can be formed into sweep bends, thus decreasing
frictional flow losses. Suction piping must be
absolutely air tight to insure accurate pumping.
After installation, test suction piping with air and
soap solution for leaks.
A strainer should be used in the suction line to
prevent foreign particles from entering the liquid
end. Any measures which prevent foreign matter
from entering and fouling the ball checks will give
increased maintenance free service.
It is preferable to have the suction of the pump
ooding by having the liquid end located below the
level of the uid in the supply tank.
When pumping liquids at temperatures near the
boiling point, provide sufcient suction head to
prevent “ashing” of the liquid into vapor when it
enters the liquid end on the suction stroke.
If suction piping is long, particularly at stroke
speeds greater than 70 strokes per minute, the
suction piping should always be larger than tting
size to prevent starving the pump.
Sealed piping, sufcient suction pressure, and
properly adjusted packing are absolutely necessary
for accurate and stable pump operation.
3.8 DISCHARGE PIPING
Install adequate size piping to prevent excessive
pressure losses on the discharge stroke of the
pump. Maximum pressure at the discharge tting
on the liquid end must be kept at or below the
maximum pressure rating as shown on the pump
data plate. The peak ow of this type of pump
during the discharge stroke is approximately three
times the average ow rate (because of harmonic
motion of the plunger) and discharge piping should
be sized accordingly.
The pump will not deliver a controlled flow if
the discharge pressure is less than the suction
pressure. Piping should be arranged to provide at
least 5 psi (34.5 kPa) positive pressure differential
from the discharge side to the suction side.
There are a number of ways to create an articial
discharge pressure, such as the use of a vented
riser or a back pressure valve.
3.9 PIPING CONCENTRATED
SULFURIC ACID
The liquid ends of pumps with plungers less than
5/8” in diameter, designed for 20 gph delivery
or less, are too small to tolerate the sludge in
commercial concentrated sulfuric acid. However,
even these pumps will serve in such applications
if the piping system is modied as follows:
1. Install a sulfuric acid tank, which has an
unused portion below the tank outlet to the
suction line to collect sludge from the system.
(Maximum pressure / sludge trap is 20 psig.)
2. Ensure pump suction is ooded.
3. Use piping material identical to liquid end
material: install steel pipe to steel liquid
end. Never connect iron to steel or serious
galvanic corrosion will occur.

7Instruction Manual
SECTION 3 - INSTALLATION
4. Filter sludge by installing a glass wool lter
or Milton Roy Sludge Trap in the suction line.
The rst and last of these precautions will benet
any size pump by removing the high proportion of
sludge in this acid, which can foul or clog pump
check valves.
Figure 4 illustrates a typical sludge trap and
Figure 5 indicates a typical installation showing a
strainer (Sludge trap) near the tank.
3.10 SUCTION LIFT CONDITIONS
Disc Diaphragm Liquid End pumps are designed
to operate with process liquid supplied at or
above atmospheric pressure. Although these
pumps can move liquids supplied at less than
atmospheric pressure, the resulting suction lift
must remain constant. The intent is that the
piping must be designed to provide an adequate
net positive suction head (NPSH). Obtain our
NPSH Calculation software at the Milton Roy
Web site (www.miltonroy.com). If assistance
in determining NPSH is needed, contact the
Milton Roy Aftermarket Service department.
Figure 5. Typical Installation
Figure 4. Typical Sludge Trap

8Instruction Manual
SECTION 4 - OPERATION
4.1 INITIAL START-UP
After installing the pump perform the following
operations before placing the pump in routine
service.
Do not operate the pump without liquid in the liquid
end. Purge air to ensure proper operation.
NOTE: (pump start-up time)
Once the required steps are completed and
the unit is running, patience is necessary until
all air has been removed from the hydraulic
chambers and uid. This may take an hour
or in some cases overnight. It is helpful at the
initial startup to relieve the discharge pressure
so that uid and air can evacuate more easily.
Once this natural air purge occurs, the pump
ow will increase to meet the rating. Inadequate
ow, in most cases means more running time is
required until proper operation can be achieved.
1. Connect all piping and purge air as required.
2. Fill drive-end chamber (the end with gears and
connecting rod) to the top of the crosshead with
SHC 629 or other approved gear oil.
3. Fill the displacement chamber through each
of the three towers located on the top of the
displacement chamber with MIL-H-5606A
(or suitable) hydraulic oil. The towers contain
the entire volume of hydraulic oil required to
operate the diaphragm liquid end. The towers
contain the air bleed / relief valve assembly, the
hydraulic chamber vent, and the hydraulic site
glass. Each tower should operate approximately
one half full during normal operation. The sight
glass and vent plugs should remain OFF until
after completion of initial start up. After initial
new pump start up, it is not necessary to
remove these items during subsequent starting
procedures.
NOTE:
New pumps received from factory are pre-lled
with Hydraulic oil and primed. This section is
only applicable when rebuilding liquid end
NOTE:
The catchall chamber, located between the
displacement chamber and the main drive
end, normally runs dry for the low ow disc
diaphragm design. Gear oil can carry over to
this chamber if the oil level is too high, or if the
cross-head seal leaks. Hydraulic oil can carry
over to this chamber if the plunger seal leaks,
or, if the displacement chamber sealing screws
are not installed. These 1/4-20nc-1/2 screws
are located in the rear displacement chamber.
To inspect these screws, the displacement
chamber must be removed from the main drive
housing. Normally, these fasteners are installed
at the Milton Roy, and do not require inspection
or service.
4. Loosen the oil rell valve, located under the
displacement chamber, and allow a small
amount of hydraulic oil to drain out from this
location. Do not remove the set screw this will
allow hydraulic oil to ll all internal cavities.
Re-tighten the oil rell valve. Re-check the oil
level in the towers. Top OFF if required. It is not
necessary to perform this step after the new unit
start up is completed. The oil rell valve does
not require adjustment after initial start up, or
during normal operation.
5. Purge air to ensure proper operation. Adjust the
relief valve hex-head screw counter clockwise
to relieve the pressure and allow oil and air to
ow as required during start up.
6. Check motor rotation. A pump rotation arrow
is located on the motor ange. Proper motor
rotation is required for pump operation.
Additional information regarding the operation
and start-up of the Milroyal®drive can be found
in instruction manual 53941.
7. Set the micrometer pump stroke adjustment
knob at zero percent (0%).
8. Check to make sure that all process supply and
discharge valves are open. Inspect the process
system for leaks. Verify that all necessary
accessories are installed.
9. Start the pump.

9Instruction Manual
SECTION 4 - OPERATION
KEEP HANDS AWAY FROM
RECIPROCATING PLUNGER,
CROSSHEAD, AND GEARS.
10. Listen for unusual noises in the drive assembly
and motor.
11. Adjust the micrometer stroke adjustment knob
to one hundred percent (100%).
12. Inspect the towers on the displacement
chamber. Hydraulic oil should be rising and
falling during the stroking sequence of the
pump. Remaining air that is trapped in the
displacement chamber will be purged through
the relief valve tower.
13. Slowly adjust the relief valve hex screw
clockwise until the pump begins to build
pressure. Normally, the pressure relief valve
is factory set to open at a pressure slightly
above the pump maximum operating discharge
pressure. Do not set the valve at pressures
greater than 3500 PSIG.
NOTE:
To adjust the relief valve rst operate the pump
against a system operating pressure.
1. Install a pressure gauge, with a range higher
than the desired relief pressure at the pump
discharge connection.
2. Install a shut-OFF valve downstream from the
pressure gauge.
3. Set micrometer control knob to 50% capacity.
4. Open shut-OFF valve. Start pump; pump
process liquid to drain or other safe point to
establish proper pumping action.
OPERATING THE LOW FLOW
DISC DIAPHRAGM AT PRES-
SURES HIGHER THAN 3500 PSIG AND A CLOSED DISCHARGE
LINE MAY CAUSE EQUIPMENT DAMAGE OR BODILY HARM.
CONTACT MILTON ROY IF PROPER RELIEF VALVE ADJUST-
MENT CANNOT BE ACHIEVED.
5. Close shut-OFF valve (“dead head” the pump)
and closely watch pressure increase on
pressure gauge. Adjust the hydraulic relief valve
hex head screw until the proper set pressure is
achieved. If pressure exceeds desired value,
quickly open shut-OFF valve to relieve pressure
in process line.
6. Loosen relief valve adjustment screw and
repeat step 5 until maximum pressure gauge
reading equals the relief valve pressure setting
desired.
7. After setting the relief valve, ensure shut-OFF
valve is fully open. Remove pressure gauge
from line, or leave in place, as desired, and
place pump in routine service.
4.2 MAINTENANCE
Hydraulic Oil Inspect and replace hydraulic
oil on the schedule provided.
Oil in gearbox Mobil SHC 629.
Oil in
displacement
chamber
MIL-H-5606A or ATF.
DO NOT INSTALL CHECK VALVES
IN THE IMPROPER DIRECTION.
INSTALL CHECK VALVES WITH THE FLOW ARROW POINTING
IN THE DIRECTION OF PROCESS FLOW (IE. SUCTION SIDE
ARROW POINTS INTO THE LIQUID END; DISCHARGE SIDE
ARROW POINTS OUT OF THE LIQUID END). TURN CHECK
VALVE ASSEMBLIES INTO LIQUID END BY HAND. DO NOT
OVERTIGHTEN, DAMAGE TO THE CHECK VALVES MAY
OCCUR.
4.3 CHECK VALVES
Maintain and service ball-check valves according
to those instructions included in manual 53941.
Low flow disc diaphragm pumps have had
several design changes and check valves are not
interchangeable (See table 1). Before buying RPM
kits for units in the eld, contact factory service.

10 Instruction Manual
SECTION 4 - OPERATION
4.4 DISASSEMBLY
Remove and disassemble check valves as follows:
1. Unscrew check valve assembly from diaphragm
head.
2. Reassemble check valves in reverse order
from disassembly. During reassembly, tighten
cartridge assembly nuts carefully to avoid
stripping ports.
4.5 DIAPHRAGM
Disassembly- Remove diaphragm head as follows:
1. Flush process liquid from liquid end.
2. Disconnect piping from suction and discharge
ball-check cartridges.
3. Remove bolts from diaphragm head and remove
head from displacement chamber.
PROCESS SIDE CONTOUR PLATE
AND DIAPHRAGM RETURN
BUTTON MAY COME AWAY WITH DIAPHRAGM HEAD.
4. Remove diaphragm from displacement
chamber.
4.6 REASSEMBLY
Clean all parts for reassembly, then proceed as
follows:
1. Set process side contour plate in diaphragm
head. Replace spring and diaphragm return
button as shown. Set new diaphragm in head
over contour plate and button.
2. Press the diaphragm and the button to
compress spring into the diaphragm head.
Align diaphragm in shallow counter bore in the
diaphragm head.
3. Place the head flat half way across the
displacement chamber, while holding the button
and diaphragm compressed. While holding the
head against the displacement chambers slide
the head across the displacement chamber and
align bolt holes.
4. Mount diaphragm head assembly to
displacement chamber with six socket head
bolts.
5. Tighten bolts evenly and securely to ensure
proper sealing of diaphragm. Torque to
50 ft-lbs.
6. Reconnect suction and discharge lines.
7. Test pump for leaks and then return to normal
service.

11Instruction Manual
DATE KIT
NUMBER NOMENCLATURE MATERIAL
Before 01/01/01 RPM037 Routine Maint. Kit, Mill D,
1/4” NPT Conn, (Female) 316SS
01/01/01 - 01/01/02 RPM038 Routine Maint. Kit, Mill D Checks,
1/4 NPT Both Ends, (Male) 316SS
01/01/01 - 01/01/02 RPM127 Routine Maint. Kit, MIL D Double Ball 316SS
01/01/01 - 01/01/02 RPM079 Routine Maint. Kit, MDD035 AL-20,
1/4 NPT Both Ends, (Male) AL-20
01/01/01 - 01/01/02 RPM080 Routine Maint. Kit, MDD036 HC-22,
1/4 NPT Both Ends, (Male) HC-22
After 01/01/02 RPM130 Routine Maint. Kit, MIL D Double Ball
with Face Seal 316SS
After 01/01/02 RPM190 Routine Maint. Kit, MIL D Double Ball
with Face Seal AL-20
After 01/01/02 RPM191 Routine Maint. Kit, MIL D Double Ball
with Face Seal HC-22
Table 1. Routine Maintenance Kits

12 Instruction Manual
SECTION 5 - TROUBLESHOOTING GUIDE
SYMPTOMS REMEDIES
Pump will not operate
• Liquid level is low. Add liquid.
• Blocked discharge line. Clear line.
• Liquid is frozen. Thaw liquid through pumping system.
• Fuse is blown. Replace fuse.
• Open thermal overload device in starter. Reset device.
• Broken wire. Locate and repair.
• Low voltage. Investigate and correct (wiring may be too light).
Pump not primed
• Allow suction line and pump head to ll with liquid before pumping against
pressure.
• Air trapped in hydraulic system. Loosen air bleed / relief valve assembly,
allow excess air to escape. Re-set airbleed.
Insufcient delivery
• Incorrect capacity adjustment. Readjust capacity setting.
• Incorrect pump speed. Match line voltage and frequency to pump motor
data plate.
• Trapped air in hydraulic cavities. Adjust oil relief valve counter-clockwise
to remove pressure. Repeat process of relieving pressure, observe air,
operate without pressure.
• Starved suction. Increase piping size or suction head.
• Leaky suction piping. Repair piping.
• High suction lift. Rearrange equipment to decrease lift.
• Liquid near boiling. Cool liquid or increase suction head.
• Leaky safety valve in discharge line. Repair or replace safety valve.
• High liquid viscosity. Reduce viscosity (e.g. heat or dilute liquid).
• Worn or dirty check valve seats. Clean or replace.
Erratic delivery
• Leaky suction piping. Repair packing.
• Leaky packing. Adjust or replace packing.
• Leaky safety valve. Repair or replace safety valve.
• Insufcient suction head. Raise suction tank level or pressurize tank.
• Liquid near boiling. Cool liquid or increase suction head.
• Worn or dirty valve seats. Clean or replace.
• Clogged or dirty line strainer. Clean strainer.
Motor overheating
• Totally enclosed and explosion proof motors run hotter than open motors.
• Wrong or insufcient gear case lubricant. Check oil level and type.
Replace questionable lubricant.
• Operation beyond rated capacity. Constrain operation to specications.
• Incorrect power supply. Match line voltage and frequency to pump motor
data place.
• Misalignment. Check alignment of moving parts.
Gear Oil in Catch-All • Gear oil level too high
Hydraulic Oil in Catch-All • Worn plunger seal.
• Displacement chamber sealing screws loose.

13Instruction Manual
Figure 6. Milroyal®D Disc Diaphragm Liquid End Top View

14 Instruction Manual
Figure 7. Milroyal®D Disc Diaphragm Liquid End Section View

15Instruction Manual
Item Description Part Number Quantity 316SS Alloy-20 Alloy-C22
100 Screw, Socket Head 3/8-16 X 1-3/4 405-0029-154 6 X X X
110 Washer 3/8 SAE, Plated 40476 6 X X X
120 Spring - Diaphragm Return 20626 1 X X X
130
Return Button, 316SS 20546 1 X
Return Button, Alloy-20 20995 1 X
Return Button, Alloy-C22 21006 1 X
140
Process Side Contour Plate, 316SS 20569 1 X
Process Side Contour Plate,
Alloy-20 20996 1 X
Process Side Contour Plate,
Alloy-C22 21005 1 X
150 Spring Pin 0.062x5/16 Steel 401-0001-031 2 X X X
Spring Pin 0.062x5/16 18.8 SS 401-0001-033 2 X X X
160
Diaphragm Head, Low Flow 20818 1 X
Diaphragm Head, Alloy-20 21345 1 X
Diaphragm Head, Alloy-C22 21346 1 X
170 Diaphragm Teon 0.030 Thick 20550 1 X X X
180 Contour Plate, Oil Side, Low Flow 20993 1 X X X
190 Displacement Chamber 21001 1 X X X
191 Sleeve 0.125 Id X 0.313 Od X 3/4 20465 1 X / 1/8 X / 1/8 X / 1/8
191 Sleeve 0.188 Id X 0.313 Od X 3/4 20466 1 X / 3/16 X / 3/16 X / 3/16
200 Plunger Seal, Viton 20461 1 X X X
210 Gland Cap 304SS 20452 1 X X X
0220/
0221 1/8” Plunger and Plunger Holder 20486 1 X / 1/8 X / 1/8 X / 1/8
0220/
0221 3/16” Plunger and Plunger Holder 20485 1 X / 3/16 X / 3/16 X / 3/16
230 Floating Plunger Nut 416 SS 272-9997-017 1 X X X
240 Thrust Washer Disc 219-9999-052 1 X X X
250 Thrust Washer Ring 219-9998-052 1 X X X
260 Soc Hd Scr 1/4-20x5/8 18.8 SS 405-0027-085 3 X X X
270 Soc Hd Scr 1/4-20x1 Alloy 405-0027-111 3 X X X
280 Flat Washer 1/4 18.8 SS 404-0005-012 3 X X X
290 Sight Glass 1/2 BSP Thread 20455 1 X X X
300 Breather Cap 1/2 NPT 20596 1 X X X
310
Barb, Air Bleed, 316 SS 20352 1 X
Barb, Air Bleed, Alloy-20 20528 1 X
Barb, Air Bleed, Alloy-C22 21010 1 X
320 O-Ring 2-007 - 90 Durometer 40466 1 X
FIGURE 6 & 7 PARTS LIST FOR LIQUID END ASSEMBLY (PLUNGER DIAMETERS 1/8” & 3/16”)

16 Instruction Manual
9001
1/4: NPT Double Ball Check Valve,
Suction, Used before 01/01/01,
See Figure 8
221-9997-128 1 X
9002
1/4: NPT Double Ball Check Valve,
Discharge, Used before 01/01/01,
See Figure 8
221-9997-228 1 X
9001/
9002
1/4: NPT Single Ball Check Valve,
Used between 01/01/01 and
01/01/02, Replaced by 21342,
See Figure 9
21082 1 X
1/4: NPT Single Ball Check Valve,
Used between 01/01/01 and
01/01/02, Replaced by 21326,
See Figure 9
21085 1 X
1/4: NPT Single Ball Check Valve,
Used between 01/01/01 and
01/01/02, Replaced by 21343,
See Figure 9
21086 1 X
1/4: NPT Single Ball Check Valve,
Used between 01/01/01 and
01/01/02, See Figure 9
21342 1 X
1/4: NPT Double Ball Check Valve,
Used between 01/01/01 and
01/01/02, See Figure 9
21326 1 X
1/4: NPT Double Ball Check Valve,
Used between 01/01/01 and
01/01/02, See Figure 9
21343 1 X
9001
1/4: NPT Double Ball Check Valve,
Suction, Used After 01/01/02,
See Figure 10
30733 1 X
1/4: NPT Double Ball Check Valve,
Suction, Used After 01/01/02,
See Figure 10
30722 1 X
1/4: NPT Double Ball Check Valve,
Suction, Used After 01/01/02,
See Figure 10
30735 1 X
9002
1/4: NPT Double Ball Check Valve,
Discharge, Used After 01/01/02,
See Figure 10
30734 1 X
1/4: NPT Double Ball Check Valve,
Discharge, Used After 01/01/02,
See Figure 10
30723 1 X
1/4: NPT Double Ball Check Valve,
Discharge, Used After 01/01/02,
See Figure 10
30736 1 X
PARTS LIST FOR LIQUID END ASSEMBLY FIGURES 6 & 7, CONT.
Item Description Part Number Quantity 316SS Alloy-20 Alloy-C22